I agree. Increasing priority. On the other hand there is always a high level plan at the beginning of the release where
IZ priority is not the only criteria. In this terms this definitely has a high priority.
BTW You can debug grails app even these days (although not directly supported):
1) run grails-debug run-app from command line
2) choose Debug/Attach Debugger
3) configure you breakpoints
4) inspect local variables (groovy expressions not yet supported)